1. Field of the Invention
The present invention relates to a release bearing mechanism used in friction clutches for automobiles, and particularly to a release bearing mechanism for clutches employing diaphragm springs of the pull type.
2. Description of the Prior Art
As is well known, the diaphragm spring is used to force a pressure plate against a friction facing of a clutch disk. In the clutch of the pull type, a radially inner portion of the diaphragm spring is pulled by the release bearing mechanism axially away from the clutch disk to disengage or release the clutch.
In the release bearing mechanism used in such clutch of the pull type, as disclosed in laid open Japanese patent application No. 59-197623 and Japanese patent application No. 61-90834, corresponding U.S. patent application Ser. No. 270,371, copending herewith, an extension of an inner race of a release bearing is inserted into a cylindrical connecting member, which is fixed to the inner periphery of the diaphragm spring, and is connected thereto through an intermediate member.
In this structure, the release bearing and the connecting member can be facilely disassembled and assembled by removing or attaching the intermediate member or by deforming it. In the structure disclosed in the above application No. 59-197623, the intermediate member is however formed by a snap ring or the like which can elastically and radially deflect in the assembled condition, so that the position of the intermediate member may be deviated by a centrifugal force, which may cause partial stress in the intermediate member, resulting in breakage of the intermediate member.
In the structure disclosed in the above application No. 61-90834, since the intermediate member is formed by a cylindrical or tubular member, which is closely fitted to the connecting member and the inner race, the above problem can be dissolved.
However, in the structure disclosed in the above application No. 61-90834, the inner race must be axially moved a long distance toward the clutch disk for disassembly. Therefore, in the assembled condition, the inner race must be located apart from the clutch disk with a long distance therebetween, resulting in increase of the whole axial size of the clutch. Further, the diaphragm spring must be inclined to a large extent with respect to the radial direction of the clutch in accordance with the position of the inner race, so that a large bending moment caused by the centrifugal force is applied to the diaphragm spring during the driving operation, resulting in decrease of the force applied from the diaphragm spring to the pressure plate.
U.S. Pat. No. 4,632,237 also disclosed a structure similar to the prior art stated above. In this structure, since an intermediate member can elastically and radially deflect in the assembled condition (i.e.. connected condition), a connecting member fixed to the diaphragm spring may not be strongly and stably connected to the inner race of the release bearing.